In　this　study,　a　double　spark　plugs　direct　injection　rotary　engine　is　used　to　investigate　the　effects　of　synchronous　and　asynchronous　changes　of　ignition　timing　on　combustion　and　emission　performance.　The　three-dimensional　dynamic　model　was　established　by　CONVERGE　software　and　validated　by　the　experimental　data.　The　results　indicate　that　setting　the　fuel　injector　toward　the　spark　plug　can　reduce　the　fuel　distribution　at　the　tail　of　the　combustion　chamber,　and　the　in-cylinder　mixture　inhomogeneity　index　gradually　increases　with　the　advance　of　the　ignition　timing.　Compared　with　the　synchronous　change　of　ignition　timing,　advancing　the　ignition　timing　of　the　tailing　spark　plug　can　promote　the　combustion　process.　When　the　ignition　timing　of　the　leading　spark　plug　is　too　early,　the　flame　front　will　be　irregular.　With　the　advance　of　ignition　timing,　CA　0-10　corresponding　to　synchronous　and　asynchronous　change　all　gradually　increase,　and　the　change　of　CA　10-90　is　more　stable　than　that　of　CA　0-10.　Whether　the　ignition　timing　is　changed　synchronously　or　asynchronously,　with　the　advance　of　the　ignition　time,　the　in-cylinder　pressure　shows　an　upward　trend.　The　mean　in-cylinder　pressure　corresponding　to　the　synchronous　change　with　the　same　change　amplitude　is　slightly　higher　than　that　of　asynchronous　change.　The　peak　pressure　of　16.4%　higher　than　that　of　the　original　engine　can　be　obtained　by　adopting　the　ignition　strategy　of　the　synchronous　advance　of　30　degrees　CA.　Under　this　ignition　strategy,　the　temperature　and　NOx　mole　fraction　in　the　combustion　chamber　are　all　the　lowest.